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1.
Bottlenose dolphins (Tursiops truncatus) produce individually distinctive vocalizations—referred to as “signature whistles”—that are thought to function as an individual
and conspecific recognition system for maintenance of consistent contact between individuals. Observations and playback experiments
were conducted at aquariums to study these whistle–vocal exchanges in bottlenose dolphins. Temporal patterns of vocalization
were examined by analyzing the intercall intervals between two consecutive whistles. When a second individual produced a call
that was different from the first individual’s vocalization, most of these calls were shorter than 1 s. However, when two
consecutive calls were produced by the same individual, the second call rarely occurred within 1 s of the first. These results
suggest that a second whistle may be produced by a different caller in response to the first whistle; however, in the case
of an absence of a response, the first caller is likely to give further whistles. The results of this acoustic analysis show
that the dolphins used in this study mostly used signature whistles during the recorded vocal exchanges. 相似文献
2.
Meagher EM McLellan WA Westgate AJ Wells RS Blum JE Pabst DA 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2008,178(4):529-543
This study investigated patterns of heat loss in bottlenose dolphins (Tursiops truncatus) resident to Sarasota Bay, FL, USA, where water temperatures vary seasonally from 11 to 33°C. Simultaneous measurements of
heat flux (HF) and skin surface temperature were collected at the body wall and appendages of dolphins during health-monitoring
events in summer (June 2002–2004) and winter (February 2003–2005). Integument thickness was measured and whole body conductance
(W/m2 °C) was estimated using HF and colonic temperature measurements. Across seasons, HF values were similar at the appendages,
but their distribution differed significantly at the flipper and fluke. In summer, these appendages displayed uniformly high
values, while in winter they most frequently displayed very low HF values with a few high HF values. In winter, blubber thickness
was significantly greater and estimated conductance significantly lower, than in summer. These results suggest that dolphins
attempt to conserve heat in winter. In winter, though, HF values across the body wall were similar to (flank) or greater than
(caudal keel) summer values. It is likely that higher winter HF values are due to the steep temperature gradient between the
body core and colder winter water, which may limit the dolphin’s ability to decrease heat loss across the body wall. 相似文献
3.
James J. Finneran Hollis R. London Dorian S. Houser 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2007,193(8):835-843
Envelope following responses were measured in two bottlenose dolphins in response to sinusoidal amplitude modulated tones
with carrier frequencies from 20 to 60 kHz and modulation rates from 100 to 5,000 Hz. One subject had elevated hearing thresholds
at higher frequencies, with threshold differences between subjects varying from ±4 dB at 20 and 30 kHz to +40 dB at 50 and
60 kHz. At each carrier frequency, evoked response amplitudes and phase angles were plotted with respect to modulation frequency
to construct modulation rate transfer functions. Results showed that both subjects could follow the stimulus envelope components
up to at least 2,000 Hz, regardless of carrier frequency. There were no substantial differences in modulation rate transfer
functions for the two subjects suggesting that reductions in hearing sensitivity did not result in reduced temporal processing
ability. In contrast to earlier studies, phase data showed group delays of approximately 3.5 ms across the tested frequency
range, implying generation site(s) within the brainstem rather than the periphery at modulation rates from 100 to 1,600 Hz.
This discrepancy is believed to be the result of undersampling of the modulation rate during previous phase measurements. 相似文献
4.
Chisato Yamamoto Toshiaki Ishibashi Akihiko Yoshida Masao Amano 《Journal of Ethology》2016,34(2):147-153
Reconciliation, post-conflict affiliation between former opponents, was suggested to repair the relationship between former opponents. The number of times that each former opponent initiates reconciliation may be affected by the dominance style. Despotic dominance style was suggested to restrain the initiation of reconciliation by recipients of aggression, unlike relaxed dominance style. Although reconciliation was suggested to restore relationships, reconciliation sometimes did not occur. The valuable relationship hypothesis predicts that reconciliation is more likely to occur when former opponents share a valuable relationship. However, few studies have tested this hypothesis in non-primate species. This study investigated, in captive bottlenose dolphins, which are suggested as having a relaxed dominance style, whether aggressors or recipients of aggression initiate reconciliation, and whether relationships between former opponents affect the occurrence of reconciliation. The number of times that aggressors or recipients of aggression initiate reconciliation did not differ. Recipients of aggression initiated reconciliation sooner than aggressors. These results support the prospect that recipients of aggression are not impeded in initiating reconciliation in relaxed species. Former opponents who share a more affiliative relationship were reconciled more frequently. Bottlenose dolphins were suggested to receive the benefits from individuals who shared more affiliative relationships. The valuable relationship hypothesis may be supported in bottlenose dolphins. 相似文献
5.
Venn-Watson S Smith CR Gomez F Jensen ED 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2011,181(5):667-680
Changes in hematological and serum chemistry values have been identified among older compared to younger humans. We hypothesized
that healthy bottlenose dolphins (Tursiops truncatus) 30 years and older may demonstrate similar clinicopathological changes with increasing age. Retrospective hematological
and serum chemistry data generated from routine, fasted blood samples collected over 10 to 20 years among six healthy dolphins
that lived at least 40 years were analyzed to (1) assess linear trends in blood variable values with increasing age, (2) compare
mean blood values by older age categories (30–35 years, 36–40 years, and >40 years), and (3) compare the prevalence of clinically
high or low blood values by older age categories. Absolute lymphocytes, serum globulins, and mean platelet volume increased
linearly with increasing old age. Mean white blood cells, neutrophils, serum globulins, erythrocyte sedimentation rates, serum
cholesterol, and serum triglycerides; and the prevalence of neutrophilic leukocytosis, hyperglobulinemia, and hypercholesterolemia,
were more likely to be higher as geriatric dolphins got older. A linear decrease in serum albumin with increasing age was
present for five of six animals. Serum creatinine decreased among dolphins older than 40 years compared to when they were
30–40 years old. Our study demonstrates that older dolphins have changes in hematological and serum chemistry values similar
to those found in older humans. As such, bottlenose dolphins may serve as a useful comparative model for aging in humans.
Further studies are needed to assess whether these changes are associated with negative health outcomes and whether targeted
therapeutics can help improve quality of life among aging dolphins. 相似文献
6.
Deacon NL Arnould JP 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2009,179(3):287-295
The development of cardiac control in association with terrestrial respiration patterns was examined throughout the period
of maternal dependence in Australian fur seal pups. Resting eupnoic heart rate and respiration rate were significantly correlated
(r
2 = 0.49) and both decreased with age (P < 0.05 in both cases). From an early age (1 month), pups displayed terrestrial apnoeas (18.1 ± 0.5 s) accompanied by substantial
bradycardia (127 beats min−1, a 13% decrease from eupnoic HR). Terrestrial apnoea duration increased significantly with age reaching a mean of 41 s just
prior to weaning, slightly lower than the mean dive duration (52 s) previously recorded for pups of the same age. Correspondingly,
mean apnoic heart rate decreased with age to 74 beats min−1 just prior to weaning, representing a 25% decrease on eupnoic heart rate. Importantly, concomitant with the decrease in mean
apnoic heart rate with age, an increase in the control of bradycardia was evident with the variability in instantaneous apnoic
heart decreasing such that older pups were able to maintain a low steady heart rate for the duration of the apnoea. The changes
seen in these parameters are similar to those reported during postnatal development in elephant seals (Mirounga spp.) and harbour seals (Phoca vitulina), and are considered indicative of the development of cardiac control. These findings suggest a common strategy for the development
of bradycardia control in both otariid and phocid seals. 相似文献
7.
There is a need for biological information to support current stock designations of bottlenose dolphins (Tursiops truncatus) in the Gulf of Mexico. The existence of many inshore, resident “communities” raises questions as to the relationship these
dolphins may hold with dolphins inhabiting neighboring inshore and coastal areas. In this study, population subdivision was
examined among four resident, inshore bottlenose dolphin stocks (Sarasota Bay, FL, Tampa Bay, FL, Charlotte Harbor, FL and
Matagorda Bay, TX) and one coastal stock (1–12 km offshore) in the Gulf of Mexico. Evidence of significant population structure
among all areas was found on the basis of both mitochondrial DNA (mtDNA) control region sequence data and nine nuclear microsatellite
loci. Estimates of relatedness showed no population contained a significantly high number of related individuals, while separate
AMOVAs for males and females indicated that both sexes exhibit a significant level of site philopatry. Results presented here
provide the first genetic evidence of population subdivision between the coastal Gulf of Mexico and adjacent inshore areas
along the central west coast of Florida. Such strong genetic subdivision is surprising given the short geographical distance
between many of these areas and the lack of obvious geographic barriers to prevent gene flow. These findings support the current,
separate identification of stocks for bottlenose dolphins inhabiting the eastern coastal and inshore areas of the Gulf of
Mexico. 相似文献
8.
Joanna Wiszniewski Luciano B. Beheregaray Simon J. Allen Luciana M. Möller 《Conservation Genetics》2010,11(4):1405-1419
Determining genetic connectivity of bottlenose dolphin communities helps identify evolutionary mechanisms, such as environmental
and social factors, that interact to shape dispersal in highly social marine mammals. Here, we expand on a localized study
that found marked genetic differentiation among resident dolphins (Tursiops aduncus) in the Port Stephens embayment and adjacent coastal communities, to include four additional communities inhabiting different
environment types along the New South Wales coast, Southeastern Australia. Analysis of the mitochondrial DNA control region
and seven microsatellite loci suggest the nine communities may have originated from a single ancestral population that progressively
colonised the coast in a southward direction. Gene flow among communities was predominately governed by habitat type. The
two enclosed embayments showed the highest level of genetic differentiation from other communities, while genetic differentiation
among coastal and open embayment communities generally followed a pattern of isolation by distance. Directional bias in recent
migration rates was evident, with the centrally located Hunter coast communities consisting of individuals with mixed ancestry
from the Northern, Southern and Port Stephens communities. Emigration from Port Stephens was substantially higher than in
the opposite direction, indicating there may be social barriers to dispersal created by Port Stephens dolphins. Our results
suggest that the scale of connectivity of bottlenose dolphin communities inhabiting heterogeneous environments is likely to
be affected by local habitat adaptation. This has important implications for the management of communities exposed to increasing
levels of anthropogenic disturbances, such as the intensive commercial dolphin-watching industry operating in Port Stephens. 相似文献
9.
We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan. 相似文献
10.
Bo Joakim Eriksson Noel N. Tait Graham E. Budd Michael Akam 《Development genes and evolution》2009,219(5):249-264
As the putative sister group to the arthropods, onychophorans can provide insight into ancestral developmental mechanisms
in the panarthropod clade. Here, we examine the expression during segmentation of orthologues of wingless (Wnt1) and engrailed, two genes that play a key role in defining segment boundaries in Drosophila and that appear to play a role in segmentation in many other arthropods. Both are expressed in segmentally reiterated stripes
in all forming segments except the first (brain) segment, which only shows an engrailed stripe. Engrailed is expressed before segments are morphologically visible and is expressed in both mesoderm and ectoderm. Segmental wingless expression is not detectable until after mesodermal somites are clearly distinct. Early engrailed expression lies in and extends to both sides of the furrow that first demarcates segments in the ectoderm, but is largely
restricted to the posterior part of somites. Wingless expression lies immediately anterior to engrailed expression, as it does in many arthropods, but there is no precise cellular boundary between the two expression domains analogous
to the overt parasegment boundary seen in Drosophila. Engrailed stripes extend along the posterior part of each limb bud, including the antenna, while wingless is restricted to the distal tip of the limbs and the neurectoderm basal to the limbs.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
Epigenetic modifications of histone play important roles for regulation of cell activity, such as cell division, cell death,
and cell differentiation. A SET domain consisting of about 130 amino acids has lysine methyltransferase activity in the presence
of the cosubstrate S-adenosyl-methionine. More than 60 SET domain-containing proteins have been predicted in various organisms.
One of them, the SMYD family genes which contain a SET domain and a zinc-finger MYND domain are reported to regulate cell
cycle and muscle formation. Here we examined the expression and function of smyd1 and 2 in Xenopus. smyd1 and 2 were expressed in various muscle tissues. While smyd1 expression was observed mainly in cardiac muscle and skeletal muscle, smyd2 expression was done abundantly in skeletal muscle and face region. Moreover, by loss-of-function experiments using antisense
morpholino oligonucleotides, it was suggested that smyd1 and 2 related to muscle cells differentiation. 相似文献
12.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献
13.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora:
Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii
,
Rumex densiflorus var. pycnanthus
,
R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage. 相似文献
14.
15.
Using a direct amplification of genomic DNA from two Brassica rapa forms, we obtained two homologs of the CONSTANS gene, which controls the photoperiodic induction of flowering in Arabidopsis plants. The cloned fragments of B. rapa genome were identified as members of the CONSTANS-LIKE1 class. By aligning the nucleotide sequences of the CONSTANS gene and its homologs, three classes, CONSTANS, CONSTANS-LIKE1, and CONSTANS-LIKE2, were distinctly discerned by their primary structure. The pattern of restriction fragment length polymorphisms (RFLP) of the CONSTANS homologs in B. carinata, B. juncea, B. napus, B. nigra, B. oleracea, and B. rapa were genome-specific; in addition, the CONSTANS homologs were classified by plant geographic origin, and we assume that such classification is related to plant photoperiodic response.Translated from Fiziologiya Rastenii, Vol. 52, No. 2, 2005, pp. 274–281.Original Russian Text Copyright © 2005 by Martynov, Khavkin.This revised version was published online in April 2005 with a corrected cover date. 相似文献
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18.
Poulícková A 《Folia microbiologica》2008,53(2):125-129
Single (unpaired) vegetative cells of freshwater pennate diatom Neidium cf. ampliatum differentiated into gametangia and produced a single zygote (auxospore) via a pedogamic process. The gametic nuclei fused after auxospore expansion had begun. The auxospore expanded in parallel to the apical axis of the gametangium. 相似文献
19.
Background
Gonadotropin releasing hormone (GnRH) is responsible for stimulation of gonadotropic hormone (GtH) in the hypothalamus-pituitary-gonadal axis (HPG). The regulatory mechanisms responsible for brain specificity make the promoter attractive for in silico analysis and reporter gene studies in zebrafish (Danio rerio).Results
We have characterized a zebrafish [Trp7, Leu8] or salmon (s) GnRH variant, gnrh 3. The gene includes a 1.6 Kb upstream regulatory region and displays the conserved structure of 4 exons and 3 introns, as seen in other species. An in silico defined enhancer at -976 in the zebrafish promoter, containing adjacent binding sites for Oct-1, CREB and Sp1, was predicted in 2 mammalian and 5 teleost GnRH promoters. Reporter gene studies confirmed the importance of this enhancer for cell specific expression in zebrafish. Interestingly the promoter of human GnRH-I, known as mammalian GnRH (mGnRH), was shown capable of driving cell specific reporter gene expression in transgenic zebrafish.Conclusions
The characterized zebrafish Gnrh3 decapeptide exhibits complete homology to the Atlantic salmon (Salmo salar) GnRH-III variant. In silico analysis of mammalian and teleost GnRH promoters revealed a conserved enhancer possessing binding sites for Oct-1, CREB and Sp1. Transgenic and transient reporter gene expression in zebrafish larvae, confirmed the importance of the in silico defined zebrafish enhancer at -976. The capability of the human GnRH-I promoter of directing cell specific reporter gene expression in zebrafish supports orthology between GnRH-I and GnRH-III.20.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献